I don't know if this counts or not, but, back in the old days, but, when I finally got to see Emprie (which wasn't too long after it opened) I was genuinely shocked that Vader was Luke's father. And I mean Eyes popping out of Head shocked! I couldn't figure out how he went from Skywalker to Vader. I did know Obi Wan did something involving a volcanic pit, but I couldn't figure out how you live through taking a bath in molten lava, and a part of me thought "Hmm, maybe he's lying?" and it took Jedi (and, all the stuff in the SW fan club) to convince me otherwise.
(It may also have been my long standing fued with David Prowse affecting my jugement. I was at a creation convention with a friend, and we were in line for autographs from a few people, and we had hooked up with a quartet of Star Trek geeks dressed like an away party. Anyway, David was giving a lecture and we were waiting right by where he was talking, and we got into a heated argument over who was cooler, Han Solo, or Captain Kirk - this was pre Empire. Anyway, Prowse stopped the lecture and yelled at us. Which stopped the argument dead in it's tracks. Years later I met him at a Comic Con, and at the time my husband was consdiering hosting one up where we live, so he got Prowse's contact info for a guest appearance. How times change. We never did host the Con, too much of a pain.)
I was also floored they renamed Jedi. Club members were sent all this stuff, and one of the things was a Revenge of the Jedi pencil. Which I of course used down to the nub. Then they go and change the name of the damn movie.